1. Field of the Invention
The present invention relates to a mobile information terminal apparatus carrying electronics, in particular, to the mobile information terminal apparatus, which has prodigious strength against the external environment and external impacts and has been improved in preventing a contact failure of a battery for a self-contained power supply.
2. Description of the Related Art
In general, known are various apparatuses, for example, a radio communication apparatus for a mobile telephone etc., a personal computer, a remote control apparatus, a compact type of bar code scanner, and the like as a mobile information terminal apparatus constituted by electronics.
In such a mobile information terminal apparatus, small sizing and light weighting are greatly important and thus its basic functions and basic performance are selected. The memory size of a main memory provided in a body of the apparatus is limited to the extent that basic software necessary for driving or major application software is stored. Therefore, various data are stored in a storage medium such as a detachable memory card etc. When the data are used, the main memory is mounted in the body of the apparatus.
Many of these mobile information terminal apparatuses are configured in that the memory card is inserted in a slot that opens externally and fixed by engaging with a connector, and data are exchanged. In the state that a part of the memory card described above is exposed externally, it is easy to insert and pull out the memory card. On the other hand, in this case, there is a problem such that the memory card comes out of the slot because of an external impact etc. Even a cover is provided for the opening section, there is another problem such that, in the case where the memory card is mounted, a space is made between the opening section and the memory card and, therefore, a drop of water or dust may easily come into the apparatus from the space.
For this reason, the structure for the apparatus has been considered in that such memory card is completely mounted inside the apparatus, the opening section is sealed, and the exposed part of the memory card is eliminated, so that an influence from the external environment or an impact is reduced.
A battery that serves as a driving source of the mobile information terminal apparatus can be considered as a component in which a defect owing to an impact caused by dropping mistakenly the apparatus may easily occurs. It depends on the functions, but the mobile information terminal apparatus consumes large electric power, in general. In order to lengthen the usable time as long as possible, a battery of large capacity, for example, a packed lithium ion battery etc. is used for the apparatus.
In regard to mounting of a battery, a cover of the body of the apparatus is opened and the battery is mounted in a predetermined battery case. At this time, a battery electrode and a power supply terminal on the apparatus side come into contact and connect electrically to each other. In the past, a type that a power supply terminal with lead wire connected is fitted was employed. Therefore, even the battery moved to a certain extent inside the body of the apparatus, the electric connection was not canceled as far as the fitted power supply terminal came off. However, in this type, it is troublesome to replace the battery. What's more, parts and space were required, which is an obstacle concerning its cost and miniaturization of the apparatus. In order to deal with this, the structure is employed in that a case or a guide in which a battery is fitted is formed in the body of the apparatus, and the battery electrode and the terminal on the apparatus side come into contact by only mounting the battery in the case.
In general, since the mobile information terminal apparatus is carried about with a user, the apparatus is often bumped against something or dropped. Therefore, it happens frequently that an exorbitant impact is applied to the apparatus. Taking this into consideration, the body of the apparatus is configured to absorb such impact, or formed with a cover so as to prevent from being damaged. In regard to self-contained electronics such as a memory card etc., on receiving an impact, the electronics happen to come out of connectors. Further, there happens a defect in disconnecting the contact around an internal battery, that is, between the battery and a subject terminal, or an event such that feeding is stopped.
Particularly in a battery, its weight is heavier than the other components. So, when the apparatus receives an impact, the battery has a great influence on the other components. In addition, at that time, a terminal to contact with the battery electrode is occasionally damaged. That is, the terminal is deformed so that its elasticity cannot be recovered. In this case, a contact failure occurs so that feeding is stopped. For this reason, the construction has been employed in that a power supply terminal of the apparatus is formed from platy materials including copper of resilience. Then, even the mounted battery moves to a certain extent, the electric connection is not disconnected.
FIG. 9A is a diagram showing a schematic structure with a view of the state where a battery is mounted in a conventional mobile information terminal apparatus from a side aspect (B—B direction). FIG. 9B is a view enlarging a section of a power supply terminal, and FIG. 9C is a diagram showing a structure viewed from above.
A power supply terminal 31 shown in the drawings is mounted on a printed circuit board 32 provided in the mobile information terminal apparatus. When a battery 33 is fitted, the power supply terminal 31 is brought into the state where it is pressed toward the substrate 32 by its own electrode 34. The power supply terminal 31 is manufactured by pressing a platy material including resilient copper with use of a tool, or the like.
However, in regard to the power supply terminal 31, when an external impact is applied thereto, there are cases where the platy material easily exceeds its allowable stress because of the movement or the vibration of the battery 33 and reaches the yield point of the material. In the case where the material has reached the yield point, it is difficult to recover the resilience of the material. Therefore, a contact failure occurs. Even the platy material does not reach its yield point, there are cases where the platy material of the terminal has metal fatigue owing to vibration caused by the intermittent movement of the battery, the movement generated by irregularity in parts or impacts, so that the resilience of the terminal cannot be recovered. As a result, the contact with the battery becomes unstable easily.
When feeding is stopped during the operation because of the fact described above, a processing operation is stopped. In addition to that, in the case where the apparatus does not have a backup function, the set-up conditions, data under processing, or data to be recorded are lost, thereby losing reliability.